Determination of the double bond position in long-chain 6-alkenyl salicylic acids by collisional activation

Claeys, Magda; Heuvel, H. van den; Claereboudt, J.; Corthout, J.; Pieters, Luc; Vlietinck, A. J.

doi:10.1002/bms.1200221105

Cited by 15 publications

(9 citation statements)

References 19 publications

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“…These structures were confirmed by comparison with those of literature data. 15,19,[32][33] The positions of double bonds in compounds 1, 2, 5, 6, 8, and 9 were determined from product ions by collisionally activated dissociation of [M -H + 2Li] + precursor ions, which were generated by FABMS using a Li + containing matrix. 33 Preparation of Compounds 1, 5, and 8 Derivatives.…”

Section: Methodsmentioning

confidence: 99%

Phospholipase Cγ1 Inhibitory Principles from the Sarcotestas of Ginkgo biloba

et al. 1998

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Ten phenolic compounds were isolated from the CHCl3 extract of Ginkgo biloba sarcotestas (Ginkgoaceae) as a new class of phosphatidylinositol-specific phospholipase Cgamma1 (PI-PLCgamma1) inhibitors. The substances without the long chain were ineffective. On the other hand, the activities of these compounds were dramatically decreased by acetylation of aromatic hydroxyl groups of cardanol, phenolic acid, and bilobol and by methylation of the aromatic carboxyl group of phenolic acid. The unsaturated long chain as well as the aromatic hydroxyl and carboxyl groups might play a key role for the PI-PLCgamma1 inhibitory activity. These compounds also inhibited the growth of a number of human cancer cell lines, but were less cytotoxic against a human normal colon cell line.

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Section: Methodsmentioning

confidence: 99%

Phospholipase Cγ1 Inhibitory Principles from the Sarcotestas of Ginkgo biloba

et al. 1998

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“…For example, matrix materials with acid (e.g., 2,5-dihydroxybenzoic acid) or hydroxy groups (e.g., dithranol) compete with the FA for Li ϩ and because of the high ratio of matrix to analyte, FA lithium adduction is minimized. However, highly electron-deficient matrix materials (e.g., TCNQ) readily donate Li harge remote fragmentation (CRF) has been shown by Gross and others to have considerable analytical utility because fragmentation remote to the charge site occurs without carbon skeletal rearrangements [1][2][3][4][5][6][7][8][9]. Thus, features such as double-bond and branching positions of various functional groups can be determined directly by mass spectrometry (MS).…”

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confidence: 99%

Charge-remote fragmentation of lithiated fatty acids on a TOF-TOF instrument using matrix-ionization

Trimpin

Clemmer

McEwen

2007

J. Am. Soc. Mass Spectrom.

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In numerous studies charge remote fragmentation (CRF) has been shown to be a powerful technique for determination of primary structure by allowing location of double bonds, various functional groups, and branching in a variety of compound types directly by mass spectrometry. Instrumentation and ionization methods traditionally used for CRF, however, are becoming rare, in large part because ESI and MALDI have to a significant extent replaced them. Here we demonstrate that by selecting a matrix that promotes rather than suppresses ionization of fatty acids (FA) by lithium ion adduction, and using a TOF-TOF mass spectrometer for high-energy collisional activation, CRF ions are produced that allow location of double-bond and branching positions. Further, we show that by using solvent-free MALDI sample preparation methods, thus eliminating the inherent segregation of the hydrophobic fatty acid from the hydrophilic LiCl that can occur during the evaporation of solvent, the desired [FAϪHϩ2Li] ϩ ions are greatly enhanced. Because FAs can be vaporized using laser desorption, matrix assistance in desorption of the fatty acid may occur, but is not necessary. However, the matrix plays a crucial role in enhancing or suppressing ionization. For example, matrix materials with acid (e.g., 2,5-dihydroxybenzoic acid) or hydroxy groups (e.g., dithranol) compete with the FA for Li ϩ and because of the high ratio of matrix to analyte, FA lithium adduction is minimized. However, highly electron-deficient matrix materials (e.g., TCNQ) readily donate Li ϩ to FAs because of the instability associated with being positively charged. (J Am Soc Mass

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“…5(c)) was found to be misleading as it shows a homologous ion series ( m/z 119, 133, 147, 162, 175 and 189) that is typical for charge‐remote fragmentation of long‐chain alkyl compounds 14,. 15 The high‐energy m/z 217 CID spectrum (Fig. 5(d)) reveals a neutral loss of 15 u ( m/z 202) pointing to the presence of a methyl substituent.…”

Section: Resultsmentioning

confidence: 71%

Structural characterization of chromone C‐glucosides in a toxic herbal remedy

Cuyckens

Heuvel

et al. 2002

Rapid Comm Mass Spectrometry

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Two novel compounds, 8-C-D-glucopyranosyl-7-hydroxy-5-methylchromone-2-carboxylic acid and a 2-O'-p-coumaroyl derivative thereof, were identified in a herbal tea that caused severe vomiting in a South African patient who had taken the traditional remedy to clean his stomach. For structural characterization, electrospray (ES) ionization in combination with collision-induced dissociation (CID) and tandem mass spectrometry (MS/MS) were used, as well as UV and nuclear magnetic resonance (NMR) spectroscopy. Specific ions or neutral losses generated under conditions of ES-MS/CID/MS permitted the establishment of structural features such as the free carboxyl group, the C-hexosidic part and the p-coumaroyl group. NMR spectroscopy was necessary to support the structure of the chromone-type aglycone and the glucosidic parts. Since the compounds are structurally related to aloesin and aloeresin A, which are chemotaxonomic markers of Aloe species, and have not been previously reported, we propose that they were formed by oxidative degradation during preparation of the herbal tea from an Aloe species or during its storage.

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Determination of the double bond position in long-chain 6-alkenyl salicylic acids by collisional activation

Cited by 15 publications

References 19 publications

Phospholipase Cγ1 Inhibitory Principles from the Sarcotestas of Ginkgo biloba

Phospholipase Cγ1 Inhibitory Principles from the Sarcotestas of Ginkgo biloba

Charge-remote fragmentation of lithiated fatty acids on a TOF-TOF instrument using matrix-ionization

Structural characterization of chromone C‐glucosides in a toxic herbal remedy

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